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Should all Arctic species be red-listed?

By Catherine Brahic

Just two weeks after the US decided to list the polar bear as an endangered species because of the threat of climate change, conservationists have launched a campaign to afford its diet – Arctic seals – the same protection.

The same scientists say tens of thousands more Arctic species may soon be listed as “endangered” because of a threat several decades down the line. Some conservationists argue that all Arctic species be listed.

The Center for Biological Diversity launched a petition to have ringed, bearded and spotted seals added to the US Endangered Species Act. Like the polar bear, all three species rely on ice at some point in their life cycles.

“While the polar bear may be the first Arctic species listed under the Endangered Species Act due to global warming, it will, unfortunately, not be the last,” says Shaye Wolf, a biologist with the Center for Biological Diversity.

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The Intergovernmental Panel on Climate Change estimates that between 1°C and 3°C of warming could increase the risk of extinction for up to 30% of species. Between 4°C and 5°C could cause more than 40% of species around the globe to disappear.

“Arctic sea ice is melting so rapidly in the face of global warming that every ice-dependent marine mammal is imperilled and needs the protections of the Endangered Species Act,” says Wolf.

Strict guidelines

Wendy Foden of the International Union for the Conservation of Nature (IUCN) is more cautious. “Thresholds have to be reached,” she says. While the polar bear may be the first case of the US government listing a species as endangered because of climate change, the IUCN already does this.

The IUCN listed the polar bear on its Red List of endangered species in 2006 because it deemed that its population would drop by more than 30% in three generations due to climate change, one of the IUCN’s strict rules for classifying a species as endangered.

The organisation is currently working on guidelines to help nations assess the future threat posed by climate change to individual species. It hopes to have this ready in summer 2008.

The guidelines cover existing methods&colon; the minimum and maximum temperature range and amount of rainfall needed by a species’ is determined based on its current distribution. Climate models are then used to determine where those conditions will be available in future and how far this species will have to shift to find its new niche.

Slow response

But there are limits to these methods. For example, they do not include other threats, such as poaching or deforestation, so a species could suffer more than predicted. In addition, the method does not take into account different generation spans for different species.

“So you might expect that an animal’s environmental niche will be much reduced but if it’s in 50 years and it’s something like a mouse [with a short generation time] then it couldn’t be red listed under current criteria,” says Lera Miles, senior programme officer at the UN Environment Programme’s World Conservation Monitoring Centre.

“The current system won’t fail it, but it won’t catch it as early on its decline as we’d like,” agrees Foden.

Second method

As a result, the IUCN is working on a second way of assessing the future threat to species because of climate change. “We are working with life history traits –if a species has very specific requirements, how will those be affected by climate change?” says Foden.

She and her colleagues have identified 84 traits – such as migration timing and a requirement for certain temperatures – that could make a species vulnerable. They are now engaged in a mammoth project to assess all birds, amphibians and warm water corals – 16,800 species in total – for these traits. They will present their preliminary findings in October at the World Conservation Congress.

Policy response

Once the species are listed, there remains the difficult issue of what can be done to protect them. Responding to the threat of climate change is quite different to responding to illegal poaching, they say.

“We can eliminate all other threats that might be operating on the species, such as hunting and habitat destruction,” says Foden. “This will give the species the best chance of surviving climate change. Listing species on global and federal threatened species lists will help in this regard.”

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